Abstract: A method for a user equipment to transmit a random access preamble sequence to a base station includes transmitting the random access preamble sequence generated from a Constant Amplitude Zero Auto Correlation (CAZAC) sequence to the base station, wherein the CAZAC sequence is cyclic shifted according to one of applicable cyclic shift values defined considering a value (M) representing a Doppler shift of one subcarrier spacing and a cyclic shift unit length (T), and wherein when the value (M) meets a condition of ‘P*T?M <(P+1)*T’ where (P) is an integer, one or more adjacent cyclic shift values among the applicable cyclic shift values are defined as a group and a number of the adjacent cyclic shift values within the group equals to (P).
October 28, 2011
Date of Patent:
September 4, 2012
LG Electronics Inc.
Hyun Woo Lee, Min Seok Noh, Yeong Hyeon Kwon, Seung Hee Han, Dong Cheol Kim, Jin Sam Kwak, Dragan Vujcic
Abstract: A direct conversion multi-band TV tuner includes: a plurality of RF (radio frequency) paths for processing the RF signal and for generating a plurality of processed RF signals, respectively; and a TSC (tri-state chopper) based quadrature frequency converter for receiving one of said processed RF signals and converting the received processed RF signal into a in-phase baseband signal and a quadrature baseband signals; wherein the TSC based quadrature frequency converter operates in accordance with a first set of periodic three-state control signals and a second set of periodic three-state control signals that are approximately 90 degrees offset from the first set of periodic three-state control signals.
Abstract: A frequency-mixing method includes a step of generating a first quadrature signal having a predetermined frequency, a second quadrature signal having a phase difference of about 180 degrees with respect to a phase of the first quadrature signal, a third quadrature signal having a phase difference of about 90 degrees with respect to the phase of the first quadrature signal and a fourth quadrature signal having a phase difference of about 90 degrees with respect to a phase of the second quadrature signal; a step of controlling a phase of the third quadrature signal and a phase of the fourth quadrature signal so as to control a linearity of a frequency mixer; and a step of down-converting a radio frequency (RF) signal using the first through the fourth quadrature signals. Accordingly, performance of a direct-conversion receiver (DCR) can be improved by employing a frequency-mixing device capable of enhancing a linearity of a frequency mixer.
Abstract: A mobile wireless terminal (MWT) includes multiple wireless modems. The multiple modems have their respective transmit outputs combined together to produce an aggregate transmit output. The multiple modems can concurrently transmit data in a reverse link direction and receive data in a forward link direction. The MWT is constrained to operate under an aggregate transmit power limit. Each of the multiple modems has an individual transmit limit related to the aggregate transmit power limit. An MWT controller adjusts the individual transmit power limits in the multiple modems based on an aggregate transmit power limit of the MWT and respective transmit power estimates from the modems, to cause each individual transmit power limit to track a corresponding individual modem transmit power.
October 29, 2002
April 29, 2004
Francis M. Ngai, Aziz Gholmieh, Douglas A. Gerecht, Jon J. Anderson, William R. Panton
Abstract: A multiplier (10) includes a transconductor (14) and a multiplier core (34). The transconductor (14) converts an RF voltage signal to an RF current signal. The RF current signal modulates the quiescent currents flowing in current conducting elements (23, 24), thereby generating a modulated current signal. The modulated current signal is transmitted to the multiplier core (34), where it is combined with an LO signal to generate an output signal. The transconductor (14) and the multiplier core (34) have their current conduction paths separated from each other by the current conducting elements (23, 24).
May 5, 1997
Date of Patent:
July 6, 1999
Jesus Lucidio Finol, Michael J. McGowan, Philippe Gorisse